Crystal



July 23, 1946. w. E. KUENSTLER CRYSTAL Filed Aug. 2, 1944 Waller];fiuenlsiler Patented July 23,4946

UNITED STATES PATENT OFFICE CRYSTAL Walter E. Kuenstler, Cliffside Park,N. J.

Application August 2, 1944, Serial No. 547,692

16 Claims. 171327) This invention relates to crystals of the characteremployed in radio work, such as crystals of quartz, tourmaline. or otherpiezo-electric material, and one of the objects of the invention is toprovide an improved mounting and housing means for crystals of thischaracter.

At the present time, crystals of the kind used for radio purposes, arehoused in various ways'in box-like enclosures on which a removable coveror end-piece is usually secured by means of screws or similar fasteners.The mounting of the waferlike crystal between electrodes, and thestructure of the casing itself are such that both the crystal and itsassociated elements are often subjected to the effects of climaticconditions and particularly to dampness, vibration and the entry of dustand dirt, all of which create deficiencies in operation, reduce theactivity of the crystal and result in the raising or lowering of thenatural frequency.

The present invention contemplates the provision of an air-tight,dust-proof container which will completely exclude moisture, and whichincludes an outer casing of metal serving as a shielding and aiding inthe elimination of body capacity. The invention further contemplatesmeans by which one of the electrodes may be grounded by the simpleinsertion of one of the contact pins in the proper socket aperture; itcontemplates the provision of means by which an eiiicient seal isprovided around the pins at the points where they emerge from thecasing, and it provides for an emcient seal between the outer metalliccasing and the insid housing or block of insulating ma- I terial.

In the accompanying drawing, wherein several illustrative embodiments ofthe invention are shown, Fig. 1 is a vertical sectional view of acrystal and its casing constructed as hereinafter described; Fig. 2 is aface view of the same; Fig. 3 is a vertical sectional view, taken atright angles to the View of Fig, 1; Fig. 4 is a view of the bottom ofthe crystal and housing; Fig. 5 is a vertical sectional view through amodified structure, and Fig. 6 is a sectional view through a structurein which both of the contact pins are similarly mounted.

In the structure of Figs. 1 to 4 inclusive, I indicates the portion ofthe enclosure for the crystal which I herein refer to as the housingThis part of the structure is in the form of a block of insulatingmaterial, such as glass, or any one of the numerous plastic insulationssuitable for the purpose. The housing so constructed, is provided with arecess 2 shaped to receive the crystal 3, the latter being sandwiched inthe conventional man- 2 nerJbetWeen the two electrodes 4 and 5. Held infirm. contact with the electrode 4 is a metallic plate 6 which connects,by means of a wire I, to a contact pin 8. If the pin is grounded to themetallic casing part 9 as indicated in Fig. 1, the wire 'I can beconnected to any suitable part of the metallic casing, but if the pin 8is not grounded to the metallic casing, as shown, for example, in Fig 6,the wire i is extended directly to the pin without being brought intocontact with the easmg.

Held in firm contact with the electrode 5 is a metallic plate Ill whichis electrically connected by means of the wire to a second contact pin,designated at H.

As clearly seen in Fig. 1, the contact pin ll extends well up into theinsulating material of the housing I and has its inner knurled end I2securely embedded therein.

The outer casing, preferably made of relatively thin sheet metal orother conducting material is, in the form shown, composed of twocup-shaped parts 8 and 13 which telescopically overlap as shown at 14.When the two parts 9 and 13 of the metallic casing are fitted togetherin the overlapped or telescoped relation shown, the overlapped portionsare secured together by welding, soldering or other fusing means so thatthe casing is thereupon sealed and it not only effectively prevents theentry of dust, dirt and moisture, but being of metal and preferablygrounded by connection to the pin 8 which is placed in the socket sothat it connects to the grounded side of the circult, it constitutes ashield and eliminates body capacity which, when existant, greatlyreduces the activity of the crystal and tends to alter the frequency ofit.

The lower part 9 of the metallic casing is secured to and carried by thelower part of the housing I, said casing part 9 being provided with twoapertures or holes l5 and i8 through which the contact pins 8 and IIprotrude, the edge portion of the hole l6 being insulated from pin H bybeing spaced therefrom, with a portion of the insulatin materialindicated at H, being interposed between the pin and the edge portion ofthe casing around the hole I6. Thus, a portion of the insulating housingextends through the hole l6 and insulates the pin l I from contact withthe casing part 9, and the marginal edge portion of the casing part 9around the hole I6 is embedded in the insulation to thereby provide atight joint or seal at this point. The result of this arrangement isthat a button-like projection or head [8 of insulation appears on theoutside of the metal- 3 lie casing around the pin and holds the pinspaced from the edge of the hole It, while the edge portion of thecasing is embedded in the insulation and forms a seal.

The contact pin 3, which in the embodiment of Fig. 1 is grounded to thecasing, has a metallic head l9 in which the edge portions of the casingaround the hole l are embedded to establish firm electrical contact withthe pin and form a seal around the same.

The contact plate H3 is held firmly against the electrode 5 by means ofa coil spring 20 com pressed against the plate It by means of a pressureplate 2! of insulating material, shaped to fit within the recess 2, asclearly seen in Fig. 3. In assembling the metallic casing, the top partI3 is slid or telescoped over the bottom part ii, which is secured tothe insulating housing or block l by having parts embedded therein asdescribed, the top part l3 holding the pressure plate 2| in place. Thepressure plate 2! forces the coil spring 23 against the crystalassembly, thus holding the same, including the contact plates 5 and I0,firmly together in the recess 2. If it is desired that electrode 5rather than electrode t shall be the grounded electrode, the insulatedpressure plate fil can be omitted and the spring 20 then arranged toelectrically connect plate iii to the metal casing part i3, which willthen be electrically connected to the pin 8, While pin ll will then beconnected by a wire or other means to the electrode 5 through contactplate 53.

In the embodiment of the invention shown in Figs. 1 to 5 inclusive, oneof the contact pins is shown grounded to the metallic case. In suitableconditions where this is not desired, both of the contact pins may bearranged similarly to the contact pin H, such an arrangement beingdisclosed in Fig. 6, wherein the pin indicated at Ila is insulated fromthe casing by the means disclosed in connection with the pin ll of Fig.1.

In Fig. 5 is shown a modified construction wherein the crystal is of thehorizontal or fiat type and is contained in a relatively shallowcylindrical case. Therein the housing or block of insulating material isshown at 25 and is provided in its top with a recess 26 conforming inshape to the crystal assembly, consisting of the crystal 3 sandwichedbetween the electrodes 4 and 5. The two-part metal casing consists ofthe cupshaped metal elements El and 28 which telescope as shown and whenin closed position are welded, soldered or otherwise fused together toseal them into a closed unit. The upper part 28 of the casing carries aleaf spring 29 welded or otherwise permanently secured to its underside, said spring bearing down on the electrode 5 and establishingelectrical contact therewith as well as acting to hold the crystalassembly accurately and firmly seated in the recess 2%. In thisembodiment of the invention, the contact pin 8 is directly connected tothe casing half 27 and thus is electrically connected to electrode 5through the spring 28.

It will be observed that the upper end of the contact pin ii is exposedin therecess 26, as indicated at 38, and it is thus in direct contactwith the electrode which is firmly held against the end of the contactpin it by the pressure of the leaf spring 29. Thus, with thisarrangement, no connecting wires are required, one pin being directlyconnected to the casing which is electrically connected to one electrodeby the spring 29, and the other contact pin being in direct contact withthe second electrode.

It will be obvious from the foregoing, that various modifications may bemade in the disclosed structures without departing from the spirit ofthe invention. The shape and size of the casing may be materiallyaltered; the manner in which the crystal and electrodes are held inplace may be varied materially; the connections from the electrodes tothe contact pins may be made in a number 01 ways, and the grounding andnon-grounding of one of the pins may be also done in various ways.Accordingly, while several embodiments of the invention are disclosedand modifications thereof are herein suggested, they are contemplated asbeing within the scope of the invention and the annexed claims.

What I claim is:

1. In a crystal assembly, a crystal, electrodes between which thecrystal is located, a housing of insulating material within which thecrystal and electrodes are contained, a two-part metallic casingenclosing the insulating material, one part of the metallic casinghaving an opening, a contact pin embedded in the insulating material andprojecting through the opening in the casing, said insulating materialsurrounding the pin and insulating it from the casing, the edge portionsof the casing defining said opening being embedded in the insulatingmaterial.

2. An enclosure for crystals and the like comprising, a housing ofinsulating material containing the crystal and electrodes, a metalliccasing extending over and around the insulating material, a contact pinembedded in and projecting from the housing, the casing having anopening through which the contact pin extends, the insulating materialextending through said opening around the contact pin and serving toinsulate the pin from the casing, and the edge portions of the casingdefining said opening being embedded in the insulation around the pin.

3. An enclosure for crystals and the like comprising, a housing ofinsulating material in which the crystal and electrodes are contained,an outer casing of metal enclosing the insulating housing, the casinghaving a plurality of openings through which the insulating materialprojects, the edge portions of the metallic casing around the openingstherein being embedded in that part of the insulating material whichextends through said openings.

4. In a crystal construction, a crystal, electrodes between which thecrystal is sandwiched, a housing of insulating material extending aroundthe crystal and electrodes, contact pins electrically connected to theelectrodes, a metallic outside casing! enclosing the insulating housing,said metallic casing having openings through which the contact pinsprotrude, the edge portion around at least one of the openings beingembedded in the insulating material which surrounds the contact pinextending through said opening, a part of the insulating materialforming a head portion on the outside of the metallic casing.

5. In a crystal assembly, a housing of insulating material having arecess, a crystal and electrodes mounted in said recess, a removableclosure-piece closing said recess, a contact plate disposed against eachelectrode, resilient means interposed between one of the plates and theclosure-piece for urging said plate against its electrode and forholding the crystal and electrodes in place within the recess, contactpins embedded in and extending from the insulating housing, each of saidpins being electrically connected to a contact plate, and a metallichousing enclosing the insulating housing, said metallic housing beingapertured to permit the passage of the contact pins.

6. A construction as called for in claim 5, wherein parts of theinsulating housing extend through the apertures in the metallic housing,and parts of the metallic housing defining the apertures therein areembedded in those parts of the insulating housing which pass through theopenings in the metallic housing.

7. In a crystal assembly of the character described, a housing ofinsulating material containing a crystal and electrodes, contact pinsextending from the housing and electrically connected to the electrodes,and a two-part metallic casing enclosing the housing, the parts of saidcasing being in telescoped relation and being secured together, thecasing having openings through which the contact pins protrude.

8. In a crystal assembly of the character described, a housing ofinsulating material containing a crystal and electrodes, contact pinsextending from the housing and electrically connected to the electrodes,a two-part metallic casing enclosing the housing, the parts of saidcasing being in telescoped relationship and being secured together, thecasing having openings through which the contact pins extend, parts ofthe insulating housing projecting through said openings and embeddingthe edge portions of the openings and insulating the contact pinstherefrom.

9. In a crystal assembly, an insulating housing, a metallic casingenclosing the housing, contact pins extending from the housing, one ofsaid pins being insulated from the metallic casing by interposed partsof the insulating housing, the other pin being electrically connected tothe casing, a crystal and electrodes contained within the housing, oneof the electrodes being electrically connected to one of the contactpins and the other electrode being electrically connected to themetallic casing.

10. In a crystal assembly, a block of insulation in which a pair ofcontact pins is embedded and from which parts of the pins project, theblock having a recess, a crystal and electrodes seated in said recess,the electrodes being respectively connected to the contact pins, atwo-part metal casing enclosing the block, crystal and electrodes, oneof the parts of the casing being secured to the block by having partsembedded therein, the second part of the casing telescopi- 6 callyfitting over and being secured to the first part.

11. A structure as set forth in claim 10, wherein the casing hasapertures and the embedded parts of the casing are circumferential edgeparts of one of said apertures, the contact pin extending through saidaperture and being spaced therefrom by parts of the insulating block.

12. A structure as set forth in claim 10, wherein one part of the metalcasing carries resilient pressure means operative against one of theelectrodes to establish electrical contact therewith and to hold thecrystal and electrodes in the recess in the block.

13. In a crystal assembly, a block of insulating material having arecess, a crystal and electrodes located in the recess, a cup-likemetallic shell fitted around a part of the block and having partsembedded therein, contact pins embedded in the block and extendingthrough the shell, at least one of said pins being insulated from theshell, and a metal cover member fitting over the block and extendingover a part of the shell and co-operating therewith in forming ametallic enclosure for the block, crystal and electrodes.

147 In a crystal assembly, a block of insulation having a recess, acrystal and electrodes seated therein, an enclosing metal case having apart secured to the insulation, and a cover member fitted thereover, andresilient means urged by the cover toward the crystal and electrodes tohold the same seated in the recess.

15. In a crystal assembly, a block of insulation having a recess, acontact pin embedded in the block and having an end exposed in therecess, a crystal and electrodes seated in the recess, one of theelectrodes resting against and. in electrical contact with the exposedend of the contact pin, a two-part metallic casing enclosing the block,one of the parts of said casing carrying spring means operative againstthe second electrode to establish electrical contact therewith and tohold the crystal and electrodes seated within the recess, and a secondcontact pin electrically connected to the casing.

16. In a crystal assembly, a block of insulation having a recess, a,crystal and electrodes seated in said recess, a metal case enclosing theblock, a pair of contact pins extending out of and insulated from thecase, a spring for urging the crystal and electrodes toward the recess,and a pressure plate of insulation disposed between the spring and themetal case, and means for connecting the electrodes to the contact pins.

WALTER E. KUENSTLER.

